Conventional spark plugs have, for some time, been employed for initiating combustion of fuels, particularly in internal combustion engines. Numerous attempts have been made in the past to increase the energy output of these spark plugs since it was known that these devices were relatively inefficient in maximizing the combustion of a given amount of fuel. A more thorough discussion of prior art attempts at increasing combustion efficiency may be found in copending U.S. application entitled "Combustion Initiation System", Ser. No. 119,869, filed Feb. 8, 1980, the entire disclosure of which is hereby incorporated by reference herein. As described in said co-pending application mentioned above, one successful solution to the problem consists of employing a device for initiating combustion of fuel which creates a combustion initiating plasma jet having an energy density which approaches the energy density resulting from the combustion of the fuel itself.
Several forms of an initiation device capable of producing a plasma jet having a desired high energy density level are described in the co-pending application identified above; these devices, while entirely suitable for their intended purpose, were limited however, in terms of the maximum amount of energy that could be delivered during discharge thereof.
Accordingly, it is an important object of the present invention to provide a device for producing a high energy plasma jet useful in initiating the combustion of fuels, which is capable of delivering a plasma jet capable of delivering greater energy than was heretofor possible.
Another object of the present invention is to provide a device of the type mentioned above which is compact in overall size in relation to the energy density of the discharge which it is capable of producing.
A further object of the invention, related to the foregoing object, is to provide a device of the type mentioned which includes a capacitor portion capable of storing a maximum amount of electrical energy in a minimum amount of volume.
A still further object of the present invention is to provide a device as described above which is self-cleaning of the products of combustion and therefore avoids becoming fouled with such products.
A further object of the invention is to provide an initiation device as described above which is suitably configured for use in conventional, existing internal combustion engines, without the need for significant modification of the structural components of such engines.
These and further objects of the invention will be made clear or will become apparent during the following description.